Like most investors, you probably aim for the best possible return when picking potential investments. But as consumers increasingly clamor for companies to embrace social responsibility, good corporate citizenship is becoming a vital part of many companies' success. And it can boost the performance of our portfolios, too.

CR magazine recently released its "100 Best Corporate Citizens" list for 2013, in which it rated members of the Russell 1000 large-cap index on hundreds of different elements related to responsible behavior. In the coming weeks, I'll delve into each of the seven categories that contribute to a company's overall score.

Today, we'll look at the environment ranking, which, along with employee relations, gets the highest weighting, at 19.5%. Here are the top-rated companies in the category:

Johnson Controls


Johnson & Johnson (NYSE:JNJ)

Sprint Nextel (NYSE:S)

Advanced Micro Devices (NASDAQ:AMD)

To earn their high scores, the companies above engaged in a variety of good practices, including disclosing the total amount of energy conserved through company conservation programs and disclosing their total hazardous waste generation.

Digging deeper
So what, exactly, are these companies doing right? Here are a few examples of their environmental practices:

Johnson Controls offers a detailed "Environmental Scorecard" on its website, detailing goals and achievements such as "We aim to reduce energy intensity by 30 percent by 2018 and have achieved a 11.7 percent reduction through the end of 2012" and "Our 2018 goal is to reduce waste intensity by 20 percent and we have achieved a 8.3 percent reduction through the end of 2012."

IBM, for more than 20 years, has been issuing an annual environmental report reviewing its programs and achievements. Its 2011 report (link opens PDF file) reveals the value in attention to environmental matters, noting that the company spent $114.5 million globally in 2011 on its environmental protection programs, and reaped $139.1 million in estimated savings and cost avoidance for its troubles.

Johnson & Johnson, in its "2011 Responsibility Report" (link opens PDF file), shows that among other things, it's reducing the carbon dioxide emissions in its fleet, and that 5.9% of its overall workspace is green, as it now requires  sustainability in all significant construction projects. Between 2005 and 2010, the company reduced its absolute water use by more than 9%.

Sprint's 2011 Corporate Responsibility Performance Summary report breaks out its performance against a host of objectives for the year, including the goal to "develop a plan to achieve ... our renewable energy target" (partially achieved) and "complete an assessment of Greenhouse Gas Emissions from Sprint's Supply Chain" (fully achieved). The company aims to reduce carbon dioxide by 20% by 2017, and in 2011 it increased its renewable energy use by nearly 23%.

Advanced Micro Devices also has an annual responsibility report (link opens PDF file), along with detailed information on its website, where it lists various goals and its progress toward them. For example, it aims to decrease greenhouse gas emissions by 5% between 2009 and 2014, but as of 2011, it was ahead of its target, with an 8.1% reduction in its non-manufacturing realm, and behind schedule in manufacturing, with a 1.6% increase. It aims to divert 70% of nonhazardous waste from landfills and has diverted 57% as of 2011.

Earning green while being green
Companies doing good can boost your portfolio's performance. And various other studies have suggested that socially responsible investments are at least competitive with the overall market, if not outperforming it on occasion. That's a solid motivation for even the most coolly rational investors to take social responsibility to heart.

If you're in the market for solid socially responsible candidates for your portfolio, check out the real-money portfolio run by my colleague Alyce Lomax. Out of all the portfolios in the group, hers was recently in first place.

Longtime Fool contributor Selena Maranjianwhom you can follow on Twitterowns shares of Johnson & Johnson and Ford. The Motley Fool recommends Ford and Johnson & Johnson. The Motley Fool owns shares of Ford, International Business Machines., and Johnson & Johnson. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.